• Anatomy and Cell Biology
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• v.51 no.4
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• pp.236-242
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• 2018

The dog frontal sinus may represent an alternative model dental implant research; its topographical resemblance to the maxillary sinus renders it a potentially favorable experimental environment. The aim of this study was thus to elucidate the anatomical configuration of the canine frontal sinus and histological characteristics, and to determine whether it could be a new canine experimental model for dental implant research. Twenty-four sides of canine frontal bones were harvested. The distance from the nasion to the emerging point of the lateral aspect of the canine frontal sinus was measured with the aid of Lucion software. The thicknesses of the canine frontal sinus wall were measured, and the two specimens stained with hematoxylin and eosin. The mean distance from the nasion to the emerging point of the lateral aspect of the canine frontal sinus was 16.0 mm. The mean thicknesses of the canine frontal bone at 3, 6, 9, 12, and 15 mm lateral to the midsagittal plane were 2.3, 2.7, 3.2, 3.8, and 3.7 mm, respectively. The canine frontal sinus was lined with pseudostratified ciliated columnar epithelium. These data suggest that the canine frontal sinus is a suitable alternative to the canine maxillary sinus as a model for studying various sinus augmentation protocols.

• The Journal of Korean Society for Radiation Therapy
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• v.26 no.1
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• pp.107-114
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• 2014

Purpose : The purpose of this study is evaluation for the applicability of O-MAR(Metal artifact Reduction for Orthopedic Implants)(ver. 3.6.0, Philips, Netherlands) in head & neck radiation treatment planning CT with metal artifact created by dental implant. Materials and Methods : All of the in this study's CT images were scanned by Brilliance Big Bore CT(Philips, Netherlands) at 120kVp, 2mm sliced and Metal artifact reduced by O-MAR. To compare the original and reconstructed CT images worked on RTPS(Eclipse ver 10.0.42, Varian, USA). In order to test the basic performance of the O-MAR, The phantom was made to create metal artifact by dental implant and other phantoms used for without artifact images. To measure a difference of HU in with artifact images and without artifact images, homogeneous phantom and inhomogeneous phantoms were used with cerrobend rods. Each of images were compared a difference of HU in ROIs. And also, 1 case of patient's original CT image applied O-MAR and density corrected CT were evaluated for dose distributions with SNC Patient(Sun Nuclear Co., USA). Results : In cases of head&neck phantom, the difference of dose distibution is appeared 99.8% gamma passing rate(criteria 2 mm / 2%) between original and CT images applied O-MAR. And 98.5% appeared in patient case, among original CT, O-MAR and density corrected CT. The difference of total dose distribution is less than 2% that appeared both phantom and patient case study. Though the dose deviations are little, there are still matters to discuss that the dose deviations are concentrated so locally. In this study, The quality of all images applied O-MAR was improved. Unexpectedly, Increase of max. HU was founded in air cavity of the O-MAR images compare to cavity of the original images and wrong corrections were appeared, too. Conclusion : The result of study assuming restrained case of O-MAR adapted to near skin and low density area, it appeared image distortion and artifact correction simultaneously. In O-MAR CT, air cavity area even turned tissue HU by wrong correction was founded, too. Consequentially, It seems O-MAR algorithm is not perfect to distinguish air cavity and photon starvation artifact. Nevertheless, the differences of HU and dose distribution are not a huge that is not suitable for clinical use. And there are more advantages in clinic for improved quality of CT images and DRRs, precision of contouring OARs or tumors and correcting artifact area. So original and O-MAR CT must be used together in clinic for more accurate treatment plan.

• Journal of Dental Rehabilitation and Applied Science
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• v.22 no.4
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• pp.329-340
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• 2006

Statement of problem: Damping of the peak force transmitted to implants has been reported by in vitro studies using impact forces on resin-veneered superstructures. Theoretical assumptions suggest that use of acrylic resin for the occlusal surfaces of a prosthesis would protect the connection between implant and bone. Therefore, the relationship between prosthesis materials and the force transmitted through the implant system also needs to be investigated under conditions that resemble the intraoral mechanical environment. Purpose: The purpose of this study was to analyze the fracture strength and modes of temporary prosthesis when a flange or occlusally extended structure were connected on the top of the abutment. Material and method: Modified abutments of winged and bulk design were made by casting the desired wax pattern which is made on the UCLA type plastic cylinder. Temporary crowns were made using templates on the modified abutments, and its fracture toughness and strain were compared to the traditional temporary prosthesis. To evaluate the effect of aging, 5.000 times of thermocycling were performed, and their result was compared to the 24hours specimen result. Results: The following conclusions were drawn from this study: 1. In the fracture toughness test, temporary crown's fracture line located next to the screw hole while modified designs with metal support showed fracture line on the metal and its propagation along the metal-resin interface. 2. Wing and bulk structure didn't show significant difference in the fracture toughness (p>0.05), but wing structure showed stress concentration on the screw hole area compared to bulk structure which showed even stress distribution. 3. In the fracture toughness test after thermocycling, wing and bulk structure showed increased or similar results in metal supported area while off-metal area and temporary crown showed decreased results. 4. In the strain measurement after thermocycling, its value increased in the temporary and bulk structure. However, wing structure showed decreased value in the loading point while increased value in the screw hole area. Conclusion: Wing type design showed compatible result to the bulk type that its application with composite resin prosthesis to the implant dentistry is considered promising.

• Journal of Periodontal and Implant Science
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• v.23 no.1
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• pp.56-66
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• 1993

The Langerhans cells are dendritic nonkeratinocytes found suprabasally in most stratified squamous epithelia, such as human epidermis and the epithelium of the oral mucosa including that of gingiva. After Paul Langerhans found it in the skin in 1968, there have been sturdies of it's function and distribution . Stingle et al. reported that the Langerhans cells seem able to present antigens and to stimulate T-lymphocytes. Shelley et al. discovered that they can take up contact allergens. Accordingly it has been suggested that Langerhans cells are important elements of p Peripheral cell mediated immune system. In this study, the gingival tissue of a adult periodontitis patient was taken and freeze dried. In one specimen, we used the CD1 monoclonal antbody to staining the Langerhans cell. The other specimen, we embedded in paraffin and staining it with S-100 monoclonal antibody. The purpose of this study was to use these specimens to find out the distribution, orientation, morphology of the Langerhans cell and to discover the increase or decrease of Langerhans cell in an increased inflammatory state. The results were obtained as follows : 1. Langerhans cells were distributed between the basal cell layer and spinous cell layer against the CD1 & S-100 monoclonal antibody. 2. Langerhans cessl were plentiful in the oral eptihelium, and there was very little in the sulcular epithelium. 3. There were no Langerhans cell in the junction epithelium and pocket lining epithelium. 4. The number of Langerhans cells that responsed to the CD1 & S-100 monoclonal antibody had a statistically difference. 5. As the infiltration of the lymphocyte into the connective tissue were increased, the number of Langerhans cells in the epithelium were increased. 6. As the inflammation was increased, Langerhans cells in the spinous cell layer were more increased than those of the basal layer.

• Journal of Periodontal and Implant Science
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• v.31 no.1
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• pp.225-232
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• 2001

The aim of this study was to recommend the optimal age for prevention of periodontal disease and to investigate the trend of treatment modality according to different period. From the chart recordings of the patients who had been treated periodontally from Jan. 1981 to Dec. 1995 in the dept .of periodontics, Chosun University Dental Hospital, those of the periodontally treated patients on more than 4 sixtants were selected for the present study. The distribution of the patients was counted according to the age group and the gender. And they were divided into 3 groups(group 1: 1987-1958, group 2: 1985-1990, group 3: 1991-1995) by 5 year interval according to the treated year. The periodontal treatment modalities were classified into non-surgical therapy, pocket elimination surgery, regenerative periodontal surgery, mucoginigival surgery, clinical crown lengthening, and others. The results were as follows; 1.In the distribution of the periodontally treated patients according to the age group, 40's age group was the highest, and 30's, 40's, and 50's age groups occupied more than two thirds(73%). 2.The sexual distribution of the periodontally treated patients showed that males(53.4%) were a little more than females(46.6%). Within 20's group female was higher, but within 40's male was higher. 3.Regardless of the age group and the gender, pocket elimination surgery was the most frequent treatment modality. 4.In group 1 and 2(1987-1990) the main treatment modality was pocket elimination surgery and non-surgical therapy, but in group 3(1991-1995) it was regenerative periodontal surgery and pocket elimination surgery. The above results suggest that the prevention of periodontal disease should be initiated from early twenties, and the most frequent treatment modality may be closely related with development of new material and method.

• Journal of Periodontal and Implant Science
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• v.32 no.1
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• pp.61-68
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• 2002

The objective of this study was to determine the incidence and distribution of root fusion as well as its sexlinkage in maxillary and mandibular molars. One hundred fifty patients who had eight maxillary and mandibular molars (third molars excluded) were consecutively selected for the study subjects. The subjects provided a total of 1200 molars, i.e., 600 maxillary and 600 mandibular molars. A decision about root fusion was made on the radiographic examination. If a molar had one root and/or roots fused at any part in the root surface, it was considered as having root fusion. The results showed that : (1) 14.1 % of the maxillary molars and 5.8 % of the mandibular molars had a fused root, (2) the prevalence of root fusion in the male was 33 % and 56.4 % in the female, (3) 60 % in the male and 48.8 % in the female had bilaterally paired root fusion, (4) the root fusion was most frequently observed in the maxillary second molar position, but none in the mandibular first position in this study. Within limitations of this study, it can be concluded that, in management of molars with a furcation problem, treatment options such as hemisection and root amputation should be chosen after careful evaluation of root fusion. Further studies are needed to investigate a possible relationship between root fusion and periodontal disease progression.

• Journal of dental hygiene science
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• v.14 no.4
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• pp.477-487
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• 2014

Of the many pathogenic Candida species, Candida albicans is the main fungal pathogen of humans. The oral environmental factors considered in the Candida albicans colony forming unit test contain both host and microbial factors associated with candidiasis. In particular, Candida biofilms can develop on surfaces of prosthesis. The purpose of this study was to investigate the distribution of oral Candida species between the type of prosthesis and the situation of oral environment in patient with prosthetic appliance. The patients were 30 elderly subjects with different types of prosthesis, 7 who wore denture, 12 who wore implant and 15 who wore removable orthodontic appliance. We used Candida albicans colony forming unit test using saliva to exam the distribution of Candida albicans related with 5 oral environmental factors, gender, smoking or nonsmoking, alcohol/nonalcohol consumption, the type of prosthetic appliance and its treatment duration as well as tooth brushing frequency per day. In conclusion, for the patient's gender, site in the oral cavity and the type of prosthetic appliance and its treatment duration was associated with an increase in the distribution of Candida albicans in saliva. The distribution of Candida albicans within the oral cavity performs to be modulated to varying extents by oral environmental factors and, further investigations are required to elucidate these complex interactions.

• Journal of Periodontal and Implant Science
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• v.37 no.3
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• pp.563-573
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• 2007

Genetic polymorphisms associated with aggressive periodontitis have previously been reported. Interleukin-10 is an immunoregulatory cytokine that plays a role in the pathogenesis of periodontitis. Individual capacity for IL-10 production appears to be under genetic influence, The aim of present investigation was to explore possible genetic association of IL-10 gene promoter polymorphisms with generalized aggressive periodontitis. The study population consisted of 37 generalized aggressive periodontitis patients from the Department of Periodontology, Chonnam National University Hospital and 27 control subjects, all the subjects were non-smokers, Genomic DNA was obtained from buccal swab. The IL-10promoter -597, -824, -1082 positions were genotyped by amplifying the polymorphic regions using polymerase chain reaction (PCR) , followed by restriction enzyme digestion and gel electrophoresis. IL-10-597 C (allele 1) to A (allele 2) and IL-10-824 C (allele 1) to T (allele 2) and IL-10-1082 G (allele 1) to A (allele 2) polymorphisms were examined. The results were as follows. 1. In patients, the distribution of genotypes C/C, C/A and NA at Il-10-597 was determined to be 13.5%, 37.8% and 48.7%, respectively and the distribution of genotypes at IL-10-824 was the same as that of IL-10-597. The distribution of genotypes G/G, G/A and NA at IL-10-1082 was found to be 2.7%, 16.2% and 81. 4%, respectively. No statistical difference in genotype distribution was found between the patient and control groups. 2. Allele 2 carriage rate at the three position of the IL-10 promoter region was higher in the control group than the patient group. 3. Allele 2 frequencies at IL-10-597 and -824 positions were higher in female group than male group and its difference was statistically significant(p<0.05). No significant difference in genotype distribution between the control and patient groups. Allele frequency between control and patient groups was not significantly different although allele 2 frequency at the three positions in the IL-10 promoter region appeared to be higher in control group. In conclusion, no clear association between IL-10 gene promoter polymorphisms and generalized aggressive periodontitis in Korean was observed.

• Journal of Periodontal and Implant Science
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• v.25 no.1
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• pp.14-23
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• 1995

Cyclosporin A is a powerful immunosuppressive agent commonly used for patients receiving organ transplants. Like phenytoin and the calcium channel blockers, the drug is associated with gingival overgrowth. The purpose of this study was to compare the correlation with gingival overgrowth score and clinical indices(i.e, : plaque index, papillary bleeding index, probing depth) and correlation with gingival overgrowth score and microorganism distribution in use of phase contrast microscope. After renal tranplant, taking cyclosporin A 40 patients participating in this investigation. Post - transplatation cyclosporin medication period was average $17.53{\pm}15.75$ months. In previous study reported that gingival overgrowth is an adverse side - effects seen in about 25-81% of patient taking cyclosporin A. The results were as follows : 1. Gingival overgrowth prevalence in taking cyclosporin A patients was 77.5%. Prevalence rate of region was anterior region(26 teeth, 55.3%), molar region(14 teeth, 29.8%), premolar region(7 teeth, 14.8%) in turns. Gingival overgrowth score by Angelopoulos & Goaz method was molar region($1.56{\pm}0.81$), anterior region($1.52{\pm}0.75$), premolar region($1.14{\pm}0.90$) in turns. 2. Medication period was not correlation with gingival overgrowth score. 3. Clinical indices and gingival overgrowth score were as follows. 1) Plaque index and gingival overgrowth score was significantly correlated(p

• Maxillofacial Plastic and Reconstructive Surgery
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• v.38
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• pp.1.1-1.4
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• 2016

Background: This study aimed to investigate the distribution and prevalence of intraosseous loop (anastomosis between posterior superior alveolar artery and infraorbital artery) in Koreans detected on computed tomography (CT) images taken prior to sinus augmentation surgery. Methods: From the 177 patients who underwent sinus augmentation with lateral approach at Ewha Womans University Department of Implant Dentistry, 284 CT scans were evaluated. The canal height (CH), ridge height (RH), and canal height from the sinus floor (CHS) were measured on para-axial views at the first premolar, first molar, and second molar. The horizontal positions of the bony canals in the lateral wall were also classified. One-way analysis of variance (ANOVA) and t test were used to estimate the statistical differences (p < 0.05). Results: The intraosseous loops were detected in 92 CT scans (32 %). The mean vertical height of the bony canals from the alveolar crest (CH) was $23.45{\pm}2.81$, $15.92{\pm}2.65$, and $16.61{\pm}2.92mm$ at the second premolar, first molar, and second molar, respectively. In the horizontal positions of the bony canals, intraosseous type was the most predominant. The canal heights more than 15 mm and less than 17 mm were most prevalent (33.7 %) and those under 13 mm were 12.0 %. Conclusions: The radiographic findings in this study could be used to decide the lateral osteotomy line avoiding potential vascular complication. However, only one third of the canals could be detected in CT scans; a precaution should be taken for the possibility of severe bleeding during lateral osteotomy.